Automatic well point



June 28, 1949. T, F, MOORE AUTOMATIC WELL POINT,

' 5 sheets-sheet 1 Filed Deo. 4, 1944 June 28, 1949. T. F. yMOORE 2,474,364

' AUTOMATIC WELL POINT Filed Deo. 4, 1944 Y 3 Sheets-Sheet 2 16 i l 58 WGA.

June 2s, 1949. f. F, MOORE 2,474,364

AUTOMATIC WELL POINT Filed Dec. 4., 1944 5 Sheets-Sheet 5 Patented June 28, 1949 2,474,364 AIITOMAZTICWELnBQINIr rhumascFL@-MooregMorrimBlainsN. J. Edward pper portionVA of wyvel; ypointconstructed -inacf @relance-Withmyfinyerxtorn JFigure 2 is afv"erjicalfsectionalV view ofA the lower ortionfo'f the=we11-point off-Figure Lend-being a.

Figures 3 and 4 are vertical sectional views respectively corresponding to Figures l and 2, with the plane of the sections at right angles to the latter figures;

Figure is a horizontal sectional view taken on the line 5-5 of Figure l; and

Figures 6'and'7 are'horizontal sectional views taken respectively on the lines 6-6 and l--l of Figure 2.

Like reference characters designate corresponding parts in the several figures of the drawings, wherein I generally denotes the well point body which is of elongated tubular form and comprises a cylindrical member or pipe 2 having a series of perforations or openings 3 provided therein, and axially spaced lengthwise thereof in one or more rows running vertically of the-pipe. As shown in the drawings, the perforations or openings are arranged in two rows at diametrically opposite sides of the pipe, with the perforations of each row equidistantly spaced apart. A coupling 4 is attached to the upper end-of the pipe 2 in any suitable manner, as by welding, and the interior Aof this coupling is threaded, as at 5, so that the well point may be attached in the usual manner to a pipe leading to the jetting and suction equipment of a well point system.

At the lower end of the pipe 2, there is also provided another coupling 6 which is suitably attached thereto, as by welding, and this coupling is likewise interiorly threaded, as at l, for connection with a jetting tip designated E. Disposed within the jetting tip is a diaphragm or valve seat 9 having an aperture I9 provided therein, this seat or diaphragm being secured within the tip in any suitable manner, as bywelding. Disposed within the jetting tip below the valve seat 9 is a floating ball check Ilwhich is free to move towards and away from the seat. Downward movement of the ball check Il is limited by a pin I2 extending transversely through the jetting tip 8 at such distance below the valve vseat that, when the ball check rests upon the pin, it will be spaced from the seat 9, thus uncovering the opening I0.

The lower end of the jetting tip 8 is serrated to provide a series of teeth I3 which are utilized vto assist in eroding the soil and dislodging the same, by rotary or oscillatory movement imparted to the well point during the jetting operation. These teeth I3 are preferably of a special shape, as more particularly described in my co-pending application, Serial No. 514,686, filed December 1'7, 1943, now Patent No. 2,388,640.

In order to prevent sand, stones, gravel, and other foreign material from entering the well point during the suction o r soil dewatering operation, the well point body is provided with a filter screen designated I4, which extends about the pipe 2 over the intake openings 3. This filter screen is preferably spaced from the pipe 2 by spacing means designated I5, preferably having the form of an, asbestos cord spirally wound about the pipe. The details of the filter screen I4 and the spacing meansl, together with their advantages, are fully described in my co-pending application above referred to, and for this reason, will not be repeated herein. It is to be understood, however, that these details are not essential to the present invention, since other forms of filter screens may be employed if desired. According to the arrangement as illustrated in the drawings, the upper end of the lter screen I4 is soldered or otherwise secured to the'pipe 2 and to the lower end of the upper coupling 4, as indicated at I6, and the lower end of the iilter screen termi-- nates somewhat above the lower coupling 6, and. is soldered or otherwise secured, as at Il, to a ring or collar I8 which is in turn welded, as at I9, to the pipe 2.

Fixed to the upper end.- of the pipe 2, as by welding, is a partition or diaphragm 20 which extends transversely across the same and is provided with a pair of openings therethrough, the latter openings being designated 2I. A second diaphragm or partition 22 is disposed at the bottom of the pipe 2, beingpreferably positioned between the lower end of the pipe 2 and the upper end of the jetting tip 8, so that, when the jetting tip is screwed into the coupling 6, the diaphragm 22 will be clamped firmly between the jetting tip and the pipe 2, in order to provide a good seal about the diaphragm 22. The diaphragm, together with the bottom end of the pipe 2 and upper end of the jetting tip 8, may be machined or otherwise iinished off where they bear against each other.

The lower diaphragm 22 is also provided with a pair of openings 23 which are axially aligned with the openings 2I in the upper diaphragm 20. Extending between the respective pairs of axially aligned openings 2|, 22 is a pair of tubes or pipes designated 24. These tubes 24 are preferably secured to the lower diaphragm 22, as by extending the tubes through this diaphragm and soldering or welding the projecting ends of the tubes to the diaphragm, as indicated at 25. The upper ends of the tubes 24 are preferably removably attached to the upper diaphragm 29, and for this purpose, the tubes 24 are projected through the diaphragm 2G to receive couplings 26' which are respectively threadedly engaged on the upper threaded ends of the tubes. These couplings 26 are open. at their upper ends, and merely serve as fastening means to attach the upper ends of they ktubes. 24 to the diaphragm 20, acting as hollow' nuts which may be screwed down tightly against the diaphragm. As the couplings 26 are screwed up tight against the diaphragm 20, the tubes 24 will be placed under tension. In order to make the connection of the tubes with the upper diaphragm 20 air-tight, the upper ends of the openings 2I through which the tubes extend are preferably beveled or flared outwardly, as indicated at 21, and the lower ends of the couplings .2S are also beveled in a complementary manner so that, on screwing the couplings up tight, they will seal themselves against the upper diaphragm.

It will be seen that the upper diaphragm 29 an the lower diaphragm 22, together dene a chamber between each other and within the pipe 2 which is completely isolated fromthe space within the tubes 24, since the latter tubes are open at their opposite ends respectively above the upper diaphragm 20 and below the lower diaphragm 22. Accordingly, the chamber between these diaphragms, which chamber is designated 28, may be utilized effectively as a float chamber to control the flow of water through the well p oint whenit `passes from the ground through the'iilter screen I4, and then through the openings 3 in the pipe 2, which lead into the chamber 28. The float valve mechanism will now be described in detail,

.. and may be said to comprise a pair of cylindrical float members 29, 29,-of metal or other suitable material, to which is attached a valve member 30 coacting with a valve seat 3I provided in the lower diaphragm 22. The construction and arrangey ment of this oat valve mechanism is such that it opening of the valve 30 will be aided by the vacuum influence or suction to whi'c'hfthe well point is subjected duringthe soildewateringoperation, when thewater -Tlevel rises to `a point `=whre water may be drawn rrom the 'ground `tli'rougfh the well `point without suckingfair. Tolthese ends, the oat members 2.9, 529 are .designed lto have very little buoyancy when -subm'erged'ih water, and these members are connected ytogether ini a suitable manner, as by-meansoftie-b'olts -'31", 3l at their upper and flower ends -fres'pactively,y in spaced relation -to each other, so as -toilieffti'n opposite-sides of" the tubes "24, 2'4,theflatter tubes being suitably 'spaced from each other asfto permit the oat members tomovefr'eely'upwardly and downwardly in fthe l.chamber 28 between `the upper and lower-diaphragms, 22. To'mainta'in the bat lmembers l29, -29 Yin spacedv relationto each other, spacers 3f! -aredisposed therebetween 'on therespe'ctive tie-boltsV 3 l 3'I `rIlhe arrange ment ofthetubes and float members will' be best understood 'from reference to kFigure 5 -oi fthe drawings, showing the symmetrical and comp'actly nested relation ofr t-hese elements ywithin lthe chamber 28.

Attached to the =lower 'end of l'onelof the 4float members, as vfor example, to theflowe'r `endof the oat member 29', isa link-32, the vupper'end'fvif the link being pivotally'connected at' 33- to'anfear 'or boss 3'4 ont'he 'bottom lo1 the4 float member I'2 9., and the lower end -of fthe vli'nlt l 32 l'being 'pivotally connected at -3\5fto one end of a lerve'r'3r6. "The lever'is in'turn supported by a pair of upstandin'g 'ears 31, 31 mounted upon a supporting 'plate "3B, which plate -isfrmly attached'to the tubes'24,'4, as best shown in Figure-'6 of 'the drawings, but is Lloosely tted'in the pipe 2. A pivot pin 39 extends through the earsl, 31, and the `lever 3B whichis positioned therebetween -and acts as a ful'crum for the lever. The oppositeend oflthe lever "3.1i,

beyond the kkfu'lcrurrr'is pivotally connected at toa clevis--I which is ad'ustably carried by the upper end offavalverod'42. The lower end 'ofthe Valve rod 42 isthreaded and screwedlinto the 'valve 30 which is preferably hemispherical in shape,

the valve-being"adjustably secured on'the `end'of v* :the valve rod by a jamb nut'43.

It will be observed that vthe Valve 3D 'is'locatedat the lower 'side of the diaphragm 22,'50 thatt moves in abn-upward -direction 'on closing, andin a-downwarddirection on'opening. The valveisat *f 3l is so located in the diaphragm 22" that i't Llies adjacent tov one side' ofthe well point body, .and the valve 370 is vaccordinglypositioned"iirslidalb tonta-ct withthe wan of the-jeton@tipjaatne upper end of the'latter due to the'incline'dipositin f'the 'valve rod' 212. This arrangement automat'- ica'lly `tends -to naintain'the' valve 'in proper ali'g'nment with `its seat, land this, 'together' withtli'e hemispherical shape "of the-valve, tendst'o'pr'etent the rush dfwttter'pest 'the'vaive fromfniay'lltr'i'ally interfering With 'the 'correctI allgn'titf the Valve*v on closing-"against f itsfsea't.

asf-wm be seen fromt-he drawingsythge--levers located-a substantial distance 'above' the -lower' diaphragm 22, so ythat"su'flicien't space is afforded below this lever and the `supporting'pla-'te 39 to a'ccommodate a y"certaitt-amounti of dunes which 'enter the well point th'rough'the tlte'rfscreen""'l fro and fthe :intake openings `-3-in"thepipe'2. 'These l g'the-soil ydevtlaterin'goperation.

'andfsirpporting plate '3B to accommodate these Eties JAYabove'""rtfe'r'r'ed"lto, 4they `will not interfere 'er automatic operation of the oat valve msm.

'jetI the :well point lint'o'the `ground, the upper end `tithe well -pointdunit may be attached to a-`suitab1e length pipe which is lscrewed into theupperoouplin'g 4, the pipe being inturnico'nriectedtbya eXi-blefhose-'to -a pump. lWaterf-o'r 'other jettihg 4luid is 'forced `by l"the pump, at relatively fih pressure, 'downwardly throughthe Well"\-point, wherelit ultimately lemerges at the 'bottom oithe-jetti-ngtip?. "Inpassing through the vwell point, the j'e'tting water yhows down- `watcuy ottoman :the-tubes 24, l24, yfrom whit-lathe Water lis-discharged -Iirrto the chamber f 45 below thek owerfdiaphlr'agmffflfl `1andjaboye the valve seat-@fof thetnoattmgbttii check Vvalve H. Due totl'repressure xvo'ftthe jetting -fluid, the floating ball` "fcleck'valve will be displaced downwardly against the-pin jso v'that it'occupies the position `lshown -by"`thedotted 'lines in Figures 2 and f, l:thus allowing the "jettin'g fluid 'to continue -'t-lfrroug'ih thejettingtip-foraction upon the soil 'at*theieritrfemell'owrtend o'fthe 'jettng tip. Back wastd'oi "the'etting'ui'd is prevented by the automatic ftlosing'offtne valve 'as under 'the -m- `Buen-'ce1of'"the'ibackpressure of the jetting fluid', s'othat thef'ull pressure of thejetting fluid *is maintained 4`'atttljle/'lower'end ofthe jetting tip for he purposeof .displacing the underlying soil, which *maybe v*aided by "the teeth t3 on the 'eh-dof Lthe je'ttng'tip As the soil is -loosened andscoured'taway from-beneath the well point, it'pa'sses'upw'ardiy .around the outsideof th'e well point to the surfac'eof the ground, where thewash'ed outinaterial is deposited.

"When the wellpoint Ihas vbeen sunk in the ground"to"the"dosired depth, the jetting opera tion* is discontinued, "andthe pipe which is attarhed :tothe upper coupling 5 is disconnected Tfrom"the'hose -and'theh vconnected to a header Y'cfthe'vizell,point''systerh which header is connected'to aya'cuum pump'or other suction detice'. lOn'iliscontinuing 'thejetting operation,`the waterrema'ininigiinthe hole at 'the bottom of the welkpoint, "or"the"water"in vthe surrounding soil, will iioattheball che'ckvalve II into seating en 'ga'ge'ment 'with tlrewalve seat '9, as shown in ull' lines "inFi'gure's Zand 4 of the drawings, thereby "preventingany incw of material up- Waliily `thlflugh"the bottom. of the Well poit. 1fIhe suc'tiontfaotion "oryacuum influence on 'the welkipoint therefore, "causes the ground water lt'olce drawntinto thewell point `throughthe lter Screen |`4""and*thef"in`take 'openings 3 in the pipe rwnicnfieaufrtoythe'float: chamber 28. so long as the "water 'level is high enough 'to prevent `a^l'1'"f ro"rhl'en'teiin'gfthewell. point, the float members""29,'29"viiillassume -aA position at .the .upper end of the float chamber which opens the'valvei`3ll el-vacuumfinuencelto which the well Lpoi'nt mechanical connections between the oat mem bers and this valve. The opening movement of the valve 3E is further aided, or at least materially unimpeded, bythe suction or vacuum in uence on the well point, having in view that the vacuum influence within the chamber 45 acts upon the bottom of the valve 30, which is arranged to move in a downward direction away from its seat 3|. With the valve 30 in its open position, the water from the groundy is free to pass from the float chamber 28 into the chamber 45 from which it is withdrawn upwardly through the tubes 24, 24, and thence through the pipe attached to the upper coupling 5 to the header.

Should the water level in the ground become lowered or exhausted to a point where air might be sucked into the well point, the lowering of the water level causes the float members 29, 29 to fall, and this in turn actuates the mechanical connections 32, 36, 4|, 42 to close the valve 30, which blocks the port 44 in the diaphragm 22 and prevents any air from entering the chamber 45 where it would otherwise be drawn upwardly through the tubes 24, 24 and into the well point system where it would impair the vacuum iniluence upon other well points of the system. The closing of the valve 30 is virtually produced by the dead weight of the float members 29, 29', which, as previously indicated, are designed to have very little buoyancy. Thus, the oats require no attention to keep them from absorbing water, as is normally required with ordinary oats which are customarily made of cork or balsa wood for maximum buoyancy, and which also are .so bulky as to prohibit their use in well points of relatively small diameter. In the present invention, all that is required of the float members is that they should be just buoyant eno-ugh to move easily when the vacuum inuence pulls the valve 30 downwardly away from the seat 3|. When this happens, the well point is generally full of water and the oat members are easily moved, and as the water lowers, the float members exert a continually increasing downward pressure upon the link 32, and thus forcibly pulling the valve rod 42 upwardly through the intermediary of the fulcrum lever 36, and urging the valve 3D to close against the vacuum influence prevailing in the chamber 45.

The simplicity and efliciency of my improved well point will be obvious from the foregoing description, and one of the important advantages of the new well point over those of my prior patents hereinbefore referred to, resides in the elimination of a separate valve member to prevent back waste of the jetting iluid during the jetting operation. The function of this prior separate valve member is performed by the same valve which prohibits the passage of air into the well point system, namely, the valve 30, which, accordingly, has a dual purpose. Moreover, the float valve mechanism, together with the tubes 24, 24 and diaphragm 22, can be assembled into a unitary form, according to the present inven tion, for insertion as a unit into the well point body, following which, the couplings 26, 26 are then screwed onto-the tubes 24, 24 to seal the same in the Lipper diaphragm 20 which may have previously been welded to the upper end of the pipe 2. All parts of the well point are of sturdy and relatively simple form which materially contributes to a substantial reduction in manufacturing cost, while having little or nothing to get out of order.

While the speciiic details have been herein shown and described, my invention is not coniined thereto as changes and alterations may be made without departing from the spirit thereof as dened by the appended claims.

I claim:

l., In a well point, `comprising an elongated tubular body having liquid inlet openings in the wall thereof at spaced intervals along its length, closure means at opposite ends of the body dening therebetween a oat chamber within the body normally in communication with the exterior of the body through the inlet openings aforesaid, means forming at least one open-ended jettingand-suction passage within the tubular body, said latterv means being extended from one closure means aforesaid at the top of the tubular body to the other closure means at the bottom end, through the float chamber, to isolate the jetting-and-suction passage from the oat chamber, the lower of said closure means having a passage therethrough for establishing and interruptingcommunication between the oat chamber and the lower end of the jetting-and-suction passage, a jetting tip connected to the lower end` of the tubular body and forming a continuation thereof, andcheck-valve means disposed within the jetting tip and operable to open position responsive to the passage of a jetting iluid downwardly through the jetting-and--suction passage, the combination of a valve for the passage through the lower closure means, said valve being .positioned outside the float chamber and movable towards and away from the lower side of said closure means to respectively. close and open the passage, said valve also being aided towards its passage closing position by the back pressure of the jetting fluid acting thereagainst, and a float in the float chamber operatively connected to the valve to close the same upon falling of the liquid level in the float chamber. 2. A well point as defined in claim 1, wherein the float is so constructed as to inherently have relatively little buoyancy, whereby to offer minimum resistance to movement of the float-oper- ,1 ated valve in its movements towards and away from the closure means passage, with the deadweight of the oat acting to forcibly close the Valve on falling of the liquid level in the oat chamber,

3. A well point as defined in claim 1, wherein the jetting-and-suction passage forming means and the oat each have the form of elongated tubes arranged in spaced parallel relation within the tubular body, with the float tube closed at its opposite ends and connected at its lower end to the iloat-operated valve.

4. In a well point, comprising a tubular body having screened liquid inlet openings in the wall thereof, a pair of diaphragme extending transversely across the interior of the tubular body in axially spaced relation to each other and dening a oat chamber therebetween, a plurality of jetting-and-suction tubes extending axially through the oat chamber between the diaphragms and opening into the tubular body aforesaid at their opposite ends above the upper diaphragm and below the lower diaphragm, respectively, said lower diaphragm having a passage therethrough for establishing and interrupting communication between the float chamber and the lower ends of the jetting-and-suction tubes, and a tubular jetting tip connected to the lower end of the tubular body and provided with check-valve means therein closing the jetting tip during the withdrawal of liquid from the soil amasser 5. A Well-'pointas 'del'ffndin claim f4, fwherein thfe@jettingLandsuctin tubes are''tw"o ein? num;` bei`-f arranged inspacedY parallelrelationto eachy otherLV respectively'- onioppo'sit'e *sides of the ceny' \,1'atl-axisfofy thetubularbddy,'andiiwhereinf thel'15 fioat'comprises'a pairo`fA tubularmembers, closed 1f at-*their' Yoppo'site ends andv yconnectedl -together in i spaced' parallel f relatinto "eachl otheryfwith the tubular float members arranged par'alleltdthe jettingL-andsuctiotubes and respectively disposed on opposite sides of a plane passing through the central axis of the jettirig-andesuction tubes.

6. yA well-point as fdeneddn -c1aim-4, wherein the connection between the float-and diaphragm-1 passage controlling valvc comprises a link pivotally connected atone end-to "theoatfand dependingftherefrom, a lever l`pivotally supported be'tweenitsfends in the tubular body for frockingl movements-in opposite directionsabout yank axis? transversely related to the central axis of the tubular body, said lever being pivotally connected at one end to the lower end of the link aforesaid, and a valve rod pivotally connected at one end to the opposite end of the lever and extending through the passage in the lower diaphragm for connection at its other end to the valve.

7. A well point as dened in claim 4, wherein the connection between the float and diaphragm passage controlling valve comprises a link pivotally connected at one end to the float and depending therefrom, a lever pivotally supported between its ends in the tubular body for rocking movements in opposite directions about an axis transversely related to the central axis of the tubular body, said lever being located a substantial distance above the lower diaphragm and the valve-controlled passage therein and pivotally connected at one end to the lower end of the link aforesaid, and a valve rod pivotally connected at one end to the opposite end of the lever and extending through the passage in the lower diaphragm for connection at its other end to th-e valve.

8. A well point as defined in claim 4, wherein the valve-controlled passage through the diaphragm is located near the wall of the tubular body, and the valve coacting with said passage is slidably engageable with the wall of the tubular body so as to automatically align the valve with the passage in the diaphragm.

9. A well point as defined in claim 4, wherein the valve is hemispherical in shape and arranged with its spherical surface next to the diaphragm and adapted to seat in said passage on closing the valve.

10. A well point as dened in claim 4, wherein the connection between the float and diaphragm passage controlling valve comprises a link pivotally connected at one end to the iloat and depending therefrom, a lever pivotally supported between its ends in the tubular body for rocking movements in opposite directions about an axis transversely related to the central axis of the tubular body, said lever being pivotally connected at one end to the lower end of the link aforesaid', andf:valvefrod-pivotally connected'at i one-ndfto'fthe opposite endE of ithefleveran'd' ex--` ten'ding" Yldovvnwardly-thereirorri 'eat' an -Y inclina-` tion towards E'the eentralaxi's of the 1tubular' body, tliroughf'the' passage 'in the 'lower' 'diaphragm for coririecti'onv fa'tfits' other' end to thevalve v-A 4Well' 'poinljs defined "in clalinni, wherein the etang'#andL'sucnlo'n'i tubes* are 1 extended thrughthe@ upper-and lower 'diaphragms fand are rconnected!theretoin 'fluid-"ti'ghtsealedLA rela-f f 13;'-"-A well' point asiden'e'din lclaim-4,'- wherein` thef "jettingeandsuctionfA tubes Vare extended througlf*s fthe upper",Y and lowert :diaphra'gms and aref orinectedtheret inf'fluiditight sealedrelai tion, he conn-ectibn@with 4r'onefdf the diaphragms having the form of tubular coupling vmembershav'irig threaded engagement-with vthe endsvof the respective 'tubsian'dabutting the diaphragm in 14E-*A wellfpointas'denedlin claim 4, whereinif' theiiupper tdia.plfrfagrril"'is rigid'lywsecured'fto the* tubiilarfv'bo'dy; and the vlower vdiaplirag'inis seated-"fi on the lower end of the tubular body and releasably clamped between the same and the upper end of the jetting tip.

l5. A well point as defined in claim 4, wherein the jetting-and-suction tubes, the oat, the lower diaphragm, and the iloat-actuated valve, together have the form of a unitary assembly which is bodily insertible as a unit into the tubular body, and removable therefrom.

16. A well point as defined in claim 4, wherein the float is connected to the float-actuated valve by means including a lever fulcrumed between its opposite ends for rocking movements in opposite directions about a, horizontal axis and supported by the jetting-and-suction tubes.

17. A well point as defined in claim 4, wherein the float is connected to the float-actuated valve by means including a lever fulcrumed between its opposite ends for rocking movements in opposite directions about a horizontal axis and attached to the jetting-and-suction tubes by a supporting plate arranged transversely within the tubular body and having portions of its marginal edges spaced from the surrounding wall of the tubular body.

18. In a well point, comprising a tubular body adapted to be sunk in fluid-containing soil for withdrawing the liquid therefrom, said tubular body having a plurality of screened liquid inlet openings in the wall thereof leading into a chamber which is closed at its upper end and provided with a port at its lower end, and a jetting-andsuction conduit extending axially through the tubular body from a point above said chamber to a point below the port at the bottom thereof, whereby the now of liquid in either direction through the letting-and-suction conduit will be isolated from the chamber, the combination of single valve means for the port at the lower end of the chamber, said valve means being below. the chamber and movable towards and away from the port to respectively close and open the port responsive to the fall and rise of the liquid level in said chamber, and said valve means being also automatically operable responsive to the passage of a jetting fluid through the jettingand-suction conduit to close the port at the bottom of the chamber and thereby prevent back waste of the jetting uid into the chamber and outwardly through the liquid inlet openings.

19. In a well point, comprising a tubular body adapted to be sunk in uid-containing soil for withdrawing the liquid therefrom, said tubular body having a plurality of liquid inlet openings in the wall thereof leading into a chamber which is closed at its upper end and provided with a port at its lower end, and means for selectively conveying jetting and suction fluids through the tubular body in isolated relation to the chamber aforesaid, the combination of a valve head, a valve seat, said valve head engaging the valve seat on upward movement of the valve head responsive to the liquid level in said chamber to prevent the entrance of air into the jetting and suction uid conveying means and also operable responsive to the passage of a jetting iiuid through the conveying means to prevent back waste of the jetting fluid into the chamber and out through the liquid inlet openings.

20. In a well point, comprising a tubular body adapted to be sunk in fluid-containing soil for withdrawing the liquid therefrom, said tubular body having a plurality of liquid inlet openings in the wall thereof leading into a chamber which is closed at its upper end and provided with a 12 port at-its lower end, a plurality of jetting-andsuction tubes extending through the tubular body from a point above the chamber aforesaid to a point below the port at its lower end,

a second chamber located below the first-menl tioned chamber and normally in open communication with the lower ends of the jetting-andsuction tubes, and a check-Valve arranged below the second chamber, the combination of a valve arranged in the second chamber and movable towards and away from the lower side of the port at the bottom of the first-mentioned chamber, and a float arranged in the first-mentioned chamber, said float being freely movable in its chamber responsive to the rise and fall of the liquid level therein, and being operatively connected to the valve in the second chamber through the port at the bottom of the rst-mentioned chamber.

THOMAS F. MOORE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name y Date 2,164,253 Moore June 27, 1939 2,176,540 Moore Oct. 17, 1939 

